Well the test depends on the doctor. Some do a finger prick although this is less reliable. Some take a vial of blood. We did the vial of blood route. Ds was fine, it didn't bother him at all, but we went with a friend and that kid cried a lot, but if you have a good pediatric phlebotomist. We went to our local children's hospital to have the blood work done, because our doc doesn't do in office draws for kids under 2.
They tested his iron at the same time, same vial etc. We got the results in a week? I don't really remember.
There is no "medication" for high lead levels unless you are so exteremly high that they need to do emergency things, but in that case there are usually symptoms.
Most of the stuff that happens if your kid test high or high-ish for lead are around lead abatement in the home or homes that your child is in, information around cleaning, diet, and places of exposure.
For instances, wet moping is better than dry sweeping. Wet moping with somethign that can be thrown away (a la swiffer etc) is great because then you don't just save the lead dust for later. SimpleGreen (a natural cleanser) binds with lead to make it more inert when cleaning it up. Don't scrap old paint that you think may be lead because of creating lead dust. Replacment windows are a wonderful way to reduce lead exposure if you have old windows with lead paint on the sashes. A diet high in iron keeps your body from absorbing lead, you must also up your viatmin C to help absorb iron. A decent amount of calicum is also important. The lead levels of soil can also be high, so having your soil tested if you have a yard or garden etc.